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31.
Lakkana Laopaiboon Niphaphat Phukoetphim Kanit Vichitphan Pattana Laopaiboon 《World journal of microbiology & biotechnology》2008,24(9):1633-1641
Biodegradation of an aldehyde biocide, glutaraldehyde (GA), in a single-stage laboratory-scale rotating biological contactor
(RBC) was studied under biocide or organic loadings (OL) of 12–66 g COD m−2 day−1 and hydraulic retention times (HRT) of 0.6–3.0 h. Biofilms on the RBC were acclimated in 180 ppm GA at a hydraulic loading
(HL) of 0.18 m3 m−2 day−1 and the HRT of 0.60 h. The results showed that under a constant initial chemical oxygen demand (COD) concentration and sufficient
mineral salts available, the degree of GA removal in the RBC system was increased with either decreasing OL or increasing
HRT. After a period of acclimation, treatment efficiency in terms of GA removal by the RBC receiving GA as a sole carbon source
was 89%. The biofilms played an important role in biodegradation of biocide in the RBCs, whereas bio-oxidation of their planktonic
counterparts was totally inhibited in the presence of 50 ppm GA. The biochemical oxygen demand (BOD) test could be used as
an appropriate analytical procedure for investigating the efficiency of wastewater treatment units when seed was acclimated
and had adequate amount. 相似文献
32.
Yoshifumi Maeda Atsuhide Yagyu Akihiko Sakurai Yutaka Fujii Hiroyuki Uchida 《World journal of microbiology & biotechnology》2008,24(6):797-804
Bacterium MEY43, an isolate from soil, produced aldehyde oxidase when it was cultivated in a medium containing methanol as
a sole source of carbon and energy. The methylotrophic bacterium was identified as Brevibacillus sp. Its cultivation in media containing other substrates, such as ethanol and glucose, resulted in little production of the
enzyme. Aldehyde oxidase purified from a cell-free extract of the bacterium was a hetero-trimeric protein comprised of large,
medium, and small subunits with molecular masses of 87, 35, and 19 kDa, respectively. Its UV/visible spectrum and the presence
of molybdenum, 5′-CMP, flavin adenine dinucleotide, iron, and acid-labile sulfur suggested that the enzyme belonged to the
xanthine oxidase family. The enzyme acted on a wide range of aliphatic and aromatic aldehydes. The K
m value for formaldehyde was 32 mM, whereas those for the other aldehydes tested were below 0.2 mM. When 10 mM glutaraldehyde
was treated with 2.0 units of the enzyme ml−1 in the presence of 100 units ml−1 catalase for 120 min, the concentration of the aldehyde decreased to below a detectable level. 相似文献
33.
Saturation transfer difference (STD) NMR experiments on Escherichia coli and Drosophila melanogaster succinic semialdehyde dehydrogenase (SSADH, EC1.2.1.24) suggest that only the aldehyde forms and not the gem-diol forms of the specific substrate succinic semialdehyde (SSA), of selected aldehyde substrates, and of the inhibitor 3-tolualdehyde bind to these enzymes. Site-directed mutagenesis of the active site cysteine311 to alanine in D. melanogaster SSADH leads to an inactive product binding both SSA aldehyde and gem-diol. Thus, the residue cysteine311 is crucial for their discrimination. STD experiments on SSADH and NAD+/NADP+ indicate differential affinity in agreement with the respective cosubstrate properties. Epitope mapping by STD points to a strong interaction of the NAD+/NADP+ adenine H2 proton with SSADH. Adenine H8, nicotinamide H2, H4, and H6 also show STD signals. Saturation transfer to the ribose moieties is limited to the anomeric protons of E. coli SSADH suggesting that the NAD+/NADP+ adenine and nicotinamide, but not the ribose moieties are important for the binding of the coenzymes. 相似文献
34.
A yeast strain, Rhodotorula sp. AS2.2241, capable of reducing acetophenone and α-bromoacetophenone with high stereoselectivity, was isolated from soil samples through a novel screening procedure in which acetophenone was supplied in vapor state as the sole carbon and energy source. The biosynthesis of the ketone reductase in the yeast cells reached a maximum of 41.0 U/l at 20 h of cultivation. The reductase isolated from the Rhodotorula sp. cells was partially purified by 52.6-fold through a single column chromatography of DEAE–cellulose. The catalytic performance of the partially purified reductase was examined, and the highest activity was observed at pH 6.5 and 50 °C. The short-chain alkyl aldehydes such as acetaldehyde and those aldehydes or ketones with a benzoyl group were found to be good substrates for the reductase. In the preparative bioreductions of 50 mM acetophenone and 2 mM α-bromoacetophenone using resting cells of Rhodotorula sp. AS2.2241, (S)-(−)-1-phenylethanol (>99.5% enantiomeric excess (e.e.), 34.7% yield) and (R)-(−)-2-bromo-1-phenylethanol (>99.9% e.e., 19.9% yield) were obtained, respectively. 相似文献
35.
Dr. M. Paula-Barbosa 《Cell and tissue research》1975,164(1):63-72
Summary Synaptic vesicle flattening can be induced in the excitatory mossy fibre endings of the rat cerebellum by prolonged immersion in aldehyde during fixation (with or without perfusion). The flattening is found in a greater percentage of vesicles if perfusion has been omitted before the prolonged immersion. This is discussed in relation to the various other factors that are thought to cause flattening and the important problem of the classification of different types of synapse.The author wishes to express his thanks to Prof. E.G. Gray, for advice and constant help; to Mrs. H. Samson and M. Lourdes Brito for technical assistance, and to the Instituto de Alta Cultura, Lisbon, for a grant. 相似文献
36.
Gender difference in enzymes related with alcohol consumption in hamster,an avid consumer of alcohol
Suk-Fan Lee Zhen-Yu Chen Wing-Ping Fong 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2001,129(3):285-293
Syrian golden hamster (Mesocricetus auratus) is extraordinary among laboratory rodents in its ability to drink alcohol. After being given a free choice between 15% ethanol and water for 5 days, both male and female hamsters derived at least 85% of the fluid intake from the ethanol solution. Analysis of the alcohol-metabolizing enzymes in alcohol-na??ve hamsters showed that the male had a higher activity of 57%, 58% and 34% in stomach alcohol dehydrogenase, liver cytochrome P450 1A2 and liver aldehyde dehydrogenase, respectively, compared with the female. The activity of lung angiotensin-converting enzyme, which influence fluid intake, was twofold higher in the male. After 4 weeks of ethanol consumption, the activities of the hepatic alcohol-metabolizing enzymes remained unchanged except cytochrome P450 2E1 which increased 42% and 88% in male and female hamsters, respectively. A reduction of ~80% in the activity of cytochrome P450 1A2 was observed in both genders. The activities of several other cytochrome P450 enzymes were also decreased. Although ethanol consumption did not increase plasma aminotransferase levels, it caused a significant increase in liver weight in female, but not male hamsters. 相似文献
37.
Recent efforts to develop cure for chronic diabetic complications have led to the discovery of potent inhibitors against aldose reductase (AKR1B1, EC 1.1.1.21) whose role in diabetes is well-evident. In the present work, two new natural products were isolated from the ariel part of Ocimum basilicum; 7-(3-hydroxypropyl)-3-methyl-8-β-O-d-glucoside-2H-chromen-2-one (1) and E-4-(6′-hydroxyhex-3′-en-1-yl)phenyl propionate (2) and confirmed their structures with different spectroscopic techniques including NMR spectroscopy etc. The isolated compounds (1, 2) were evaluated for in vitro inhibitory activity against aldose reductase (AKR1B1) and aldehyde reductase (AKR1A1). The natural product (1) showed better inhibitory activity for AKR1B1 with IC50 value of 2.095 ± 0.77 µM compare to standard sorbinil (IC50 = 3.14 ± 0.02 µM). Moreover, the compound (1) also showed multifolds higher activity (IC50 = 0.783 ± 0.07 µM) against AKR1A1 as compared to standard valproic acid (IC50 = 57.4 ± 0.89 µM). However, the natural product (2) showed slightly lower activity for AKR1B1 (IC50 = 4.324 ± 1.25 µM). Moreover, the molecular docking studies of the potent inhibitors were also performed to identify the putative binding modes within the active site of aldose/aldehyde reductases. 相似文献
38.
Alves Luís Cyrne Luisa Amaral-Collaço M.T. Gírio Francisco M. 《World journal of microbiology & biotechnology》2003,19(2):201-208
Antisera against metal(Mo)-containing dye-linked dehydrogenases from sulphate-reducing bacteria were used to screen for immunological similarities with NAD+-linked dehydrogenases detected in aerobic methanol-utilizing bacterial isolates. Out of eleven strains tested, the strains #5, 8, 9 and 11 were shown to have specific formate and aldehyde dehydrogenases displaying antibody cross-reaction against highly purified Mo-containing dye-linked dehydrogenases. The apparent molecular mass of the identified proteins observed during the antibody reaction correlated with the molecular mass of the dehydrogenases obtained after native PAGE electrophoresis. The strains #8 and 11 exhibited one formate dehydrogenase apparently of identical molecular mass 140–145 kDa, whereas strains #5, 9 and 11 synthesized aldehyde dehydrogenases with apparent molecular masses of about 110, 120 and 155 kDa (two forms) and 120 kDa, respectively. All these aerobic enzymes shared antigenic properties with the anaerobic metalloproteins, indicating the existence of structural similarities between those enzymes in spite of having different cofactor moieties. 相似文献
39.
Pablo J. González Alberto C. Rizzi Mario C.G. Passeggi 《Journal of inorganic biochemistry》2009,103(10):1342-1346
Electron transfer proteins and redox enzymes containing paramagnetic redox centers with different relaxation rates are widespread in nature. Despite both the long distances and chemical paths connecting these centers, they can present weak magnetic couplings produced by spin-spin interactions such as dipolar and isotropic exchange. We present here a theoretical model based on the Bloch-Wangsness-Redfield theory to analyze the dependence with temperature of EPR spectra of interacting pairs of spin 1/2 centers having different relaxation rates, as is the case of the molybdenum-containing enzyme aldehyde oxidoreductase from Desulfovibrio gigas. We analyze the changes of the EPR spectra of the slow relaxing center (Mo(V)) induced by the faster relaxing center (FeS center). At high temperatures, when the relaxation time T1 of the fast relaxing center is very short, the magnetic coupling between centers is averaged to zero. Conversely, at low temperatures when T1 is longer, no modulation of the coupling between metal centers can be detected. 相似文献
40.
Aldehyde dehydrogenase 1 is a putative marker for cancer stem cells in head and neck squamous cancer
Yu-Chih Chen Yi-Wei Chen Han-Shui Hsu Ling-Ming Tseng Pin-I Huang Kai-Hsi Lu Dow-Tien Chen Lung-Kuo Tai Ming-Chi Yung Shih-Ching Chang Hung-Hai Ku Shih-Hwa Chiou Wen-Liang Lo 《Biochemical and biophysical research communications》2009,385(3):307-313
Aldehyde dehydrogenase 1 (ALDH1) has been considered to be a marker for cancer stem cells. However, the role of ALDH1 in head and neck squamous cell carcinoma (HNSCC) has yet to be determined. In this study, we isolated ALDH1-positive cells from HNSCC patients and showed that these HNSCC-ALDH1+ cells displayed radioresistance and represented a reservoir for generating tumors. Based on microarray findings, the results of Western blotting and immunofluorescent assays further confirmed that ALDH1+-lineage cells showed evidence of having epithelial-mesenchymal transition (EMT) shifting and endogenously co-expressed Snail. Furthermore, the knockdown of Snail expression significantly decreased the expression of ALDH1, inhibited cancer stem-like properties, and blocked the tumorigenic abilities of CD44+CD24−ALDH1+ cells. Finally, in a xenotransplanted tumorigenicity study, we confirmed that the treatment effect of chemoradiotherapy for ALDH1+ could be improved by Snail siRNA. In summary, it is likely that ALDH1 is a specific marker for the cancer stem-like cells of HNSCC. 相似文献